COOK Curtain Style Ceiling Radiation Damper User Manual
Curtain style ceiling radiation damper, Installation instruction
1
4-3/16
A
B
C
Gemini
Fire Rated
Ceiling Assembly
3-5/8
A x B
#10 x 3/4 speed screws
2 per side minimum
6" max spacing
Grille
1/4" X 20 tpi "all-thread"
or 12 ga steel hanging wire
Hanging Vibration Isolator
(Optional)
Ceiling Radiation Damper
Structural Support
CRD Model # Gemini Fan Model
A
B
C
CRD1
120
14-1/2
12-3/8
6-3/16
CRD1
140
14-1/2
12-3/8
6-3/16
CRD1
160
14-1/2
12-3/8
6-3/16
CRD1
180
14-1/2
12-3/8
6-3/16
CRD2
220, 240
12-5/8
10-1/8
5-1/16
CRD3
320, 340
12-5/8
11-1/8
5-9/16
CRD4
420
17-5/8
12-1/4
6-1/8
CRD4
520
17-5/8
12-1/4
6-1/8
CRD4
620
17-5/8
12-1/4
6-1/8
CRD4
640
17-5/8
12-1/4
6-1/8
CRD4
720
17-5/8
12-1/4
6-1/8
CRD4
740
17-5/8
12-1/4
6-1/8
Loren Cook Company’s curtain style ceiling radiation damper models CRD1, CRD2, CRD3 and CRD4 are classified by UL to
function as heat barriers in air handling penetrations through fire resistive membrane ceiling assemblies. These dampers are
for use in lieu of hinged door type dampers in fire resistive floor-ceiling or roof-ceiling designs which contain air ducts and
specify hinged door type dampers over each duct outlet, as covered in UL’s Fire Resistance Directory. The CRD dampers can be
installed either with a specific size Loren Cook Company Model Gemini fan as a listed fan and damper assembly or as a stand-
alone damper. The following installation instructions show the recommended installation procedures for the CRD’s with the
Gemini fan. If the CRD is installed as a stand-alone damper, then a 16 ga. steel support channel must be attached to the
damper. Use 12 SWG galvanized steel wire or all thread to attach the damper to a supporting structural member. Where it is
necessary to cut a main runner or cross tee, each cut end shall be supported by a vertical No. 12 SWG hanger wire. A 1/2”
(13mm) clearance shall be maintained between the duct outlet and each cut end at main runner and cross tee. The duct outlet
shall be located so that no more than one main runner or cross tee is cut when penetrating the ceiling membrane. Consult with
local authorities that have jurisdiction with regard to local codes and guidelines regarding installation.
Curtain Style Ceiling Radiation Damper
INSTALLATION INSTRUCTION
Meets NFPA 90A requirements.
Meets BOCA, SBCCA, UBC requirements.
The City of New York 460-88-5A
California State Fire Marshall 3225-0935:102
Curtain Style Ceiling Radiation Dampers - January 2002
See details on
UL Classification Marking
on enclosed product.